Tintinalli's Emergency Medicine PDF - Neurology Chapter 164

SECTION Neurology...

SECTION Neurology 14 CHAPTER Neurologic Examination MENTAL STATUS TESTING A mental status examination is part of every patient encounter. The 164 J. Stephen Huff Andrew D. Perron observation may be brief and descriptive, such as, “The patient is awake, alert, and conversant,” or it may be quite detailed. Mental status assesses the emotional and intellectual functioning of the patient. It is important to make some assessment of mental status since the patient with an INTRODUCTION abnormal mental status cannot be relied on for an accurate medical history. In most patients, the physical examination confirms thoughts formu- Major elements of mental status testing are assessment of appear- lated during history taking that are often the key to patient evaluation. ance, mood, and insight; assessment for thought disorders or abnormal Time of onset, symptom progression, associated complaints, and exac- thought content such as hallucinations; and testing of the sensorium. erbating factors are important historical points to guide appropriate Sensorium is a term for the appropriate awareness and perception of examination and testing. The neurologic examination does not exist in consciousness. Mental status testing is covered more fully in Chapter 168, isolation from the general physical examination or imaging procedures, “Altered Mental Status and Coma.” and it is unusual for the neurologic examination to delineate a problem One key element in mental status testing is assessment of attention not already suggested by the patient’s history or general physical exami- and memory. Attention testing is easily performed with digit repeti- nation. Few findings of the neurologic examination are pathognomonic tion. The average adult of normal intelligence should be able to repeat of clinical conditions or are sufficiently specific that examination alone six or seven digits forward and four or five digits backward. Failure to secures the diagnosis. Further complicating the value of the neurologic do so may suggest confusion, delirium, or a problem with language examination is that the sensitivity and specificity of different examina- perception. Often this represents a problem with attention rather than tion techniques have not been rigorously investigated, and the degree with memory. Memory is a complex process but is often simply broken of interobserver variability is not known. The uncooperative patient or into long-term and short-term activities. Long-term memory is recall of the patient with altered mental status presents additional challenges in events of some months or years ago. Short-term memory is assessed by performing a detailed examination. asking about events of the day or by three-object recall at 5 minutes. The idea of performing a “complete” examination in the ED is imprac- State three items and ask the patient to repeat; reassess at 5 minutes to tical, because a “complete” examination frequently is neither appropriate obtain a gross assessment of short-term memory function. Failure to nor required. An adequate examination is one that is sufficient for the task repeat the items immediately after presentation is likely an indication of at hand. Examination of children follows the same framework as that for an attention problem rather than of a memory problem. adults, but even more information is gathered indirectly by observation. Evaluation by screening tools is described in Chapter 168. Other For example, interacting with a child while playing with a toy or other screening tests for depression, substance abuse, or other problems are object allows the examiner to assess vision, extraocular motion, coordina- outside the scope of this chapter. tion, and strength as the child reaches for and grasps the toy.1 Traditional In general, patients with abnormal mental status, especially atten- neurologic formulation follows a three-tiered approach: (1) Is there a tion problems or disorientation, are more likely to have medical lesion of the nervous system? (2) Where is the lesion? (3) What is the problems rather than functional or psychiatric causes. If a patient lesion? The examination detailed in this chapter is arbitrarily divided into suffers from significant inattention, it is unlikely that the examiner will eight sections with basic and advanced levels described for each section. truly be able to determine whether the primary problem is one of cogni- tion or attention. ORGANIZATIONAL FRAMEWORK Organization of the neurologic examination into a framework of subsec- HIGHER CEREBRAL FUNCTIONS tions is a convenient technique. Some of the tests grouped in a section Assessment of higher cerebral functions tests neurologic tasks that assess several aspects of nervous system function, and listing of tests in a are thought to be processed in the cerebral cortex. Language function particular section is for organizational convenience. For example, visual defines the dominant hemisphere. The majority of the population is field testing, although technically a test of higher cortical function, is right-handed; for 90% of these patients, the left hemisphere is where listed with cranial nerve testing because the examining physician may language functions reside; hence, they are referred to as left-hemisphere find it easier to evaluate visual fields during that portion of the exami- dominant. Even in left-handed patients, most will be left-hemisphere nation assessing cranial nerve function. One organizational scheme dominant for language. Thus, a large cortical stroke affecting the cor- divides the examination into eight elements: tex of the dominant hemisphere (the left hemisphere in most patients, 1. Mental status testing whether they are left- or right-hand dominant) likely will affect language 2. Higher cerebral functions functions. The nondominant hemisphere is the right hemisphere in most people. 3. Cranial nerves The nondominant hemisphere is concerned with spatial relationships. 4. Sensory examination Often a nondominant hemispheric problem is suspected in the ED when 5. Motor system the patient has consistent visual inattention to a care provider approach- 6. Reflexes ing from one side (usually the patient’s left side). Higher cerebral function pragmatically involves the assessment of 7. Cerebellar testing language. For a patient with speech that is difficult to understand, a fun- 8. Gait and station damental distinction must be made between dysarthria and a dysphasia 1101 Tintinalli_Sec14_p1101-1186.indd 1101 8/2/19 12:08 PM  1102   SECTION 14: Neurology (aphasia and dysphasia are often used interchangeably in clinical word is a correct word, but the meaning of the sentence is transformed practice). Dysarthria is a mechanical disorder of speech resulting from erroneously. A patient aphasic in speaking will also be aphasic in written difficulty in the production of sound from weakness or incoordination communication. of facial or oral muscles; this may result from a motor system problem A sequence of simple commands such as requesting the patient to (cortical, subcortical, brainstem, cranial nerve, or cerebellar), but it draw a circle and then placing numbers like the numbers on a clock may does not represent a disorder of higher cerebral function. Dysphasia is reveal constructional errors. A response consistent with dysfunction of a problem of language resulting from cortical or subcortical damage; the nondominant hemisphere might be numbering half the clock face the portion of the brain concerned with comprehension, processing, or and stopping or placing all the numbers around one half of the circle. producing language is impaired. Impairment of sensory perception on the cortical level may involve There are many different types of aphasias, but a simplified scheme is the inability to distinguish objects by touch alone. Implied in this testing sufficient for assessment in the ED.2 A description of aphasia into fluent, is that the primary sensory modalities (sharp, light touch, etc.) are intact. nonfluent, or mixed patterns is adequate for initial testing and for com- In cases of nondominant hemisphere lesions, the ability to identify municating with other physicians. objects placed in a hand, such as coins, may be impaired.  BASIC  SPECIAL CIRCUMSTANCES Normal conversation monitoring for correct responses is the common A fluent aphasia may so severely impair communication that the patient screening examination for a language disorder. If suspicion of a lan- is thought to be intoxicated or psychotic. Pay attention to the pattern of guage disorder exists, a series of assessments allows categorization of speaking—this may give the first indication of a language problem, and the aphasia. further constructional or language testing may demonstrate the pres- Test comprehension initially by the ability to follow simple com- ence of an aphasia. mands. Asking the patient to identify common objects may also be part of the assessment. Use commonly available objects, such as a watch or a pen, as a stimulus. Query the patient regarding the names of different CRANIAL NERVES parts of the objects. Ask the patient to demonstrate how an object is used. The inability to show how an object is used, assuming hearing and  BASIC motor functions are intact, may represent an apraxia, which is defined A survey of the cranial nerves is often an integral part of neurologic as the inability to perform a willed act. assessment. Much information may be gathered informally. Look for In a nonfluent aphasia (a rough synonym is motor or expressive facial asymmetry (cranial nerve VII) at rest or with movement. Lingual aphasia), the speed of language and the ability to find the correct words movement (XII) and other facial movements may be inferred during may be impaired. A common type of nonfluent motor aphasia is known conversation if articulation is good. However, a more formal approach as Broca’s aphasia. Speech may be halting and slow, with stops between often is used in examination. Most examiners start with cranial nerve II words or word fragments. in testing; cranial nerve I (olfactory) testing has infrequent application In a fluent aphasia (a rough synonym is auditory or receptive aphasia), in emergency medicine. the quantity of word production is normal or even increased. Sentences Cranial nerve II is the optic nerve active in the afferent function of light may have normal grammatical structure with normal rhythm, and and visual perception. Common tests for optic nerve function include intonation may be clearly articulated. However, language is impaired, visual acuity and stimulation for pupillary reactivity. The response to and the listener may be struck by peculiarities of conversation that lack bright light stimulation involves direct and indirect (consensual) pupillary appropriate content. Incorrect words may be substituted within sen- responses. This is a reflex arc, with the afferent limb being cranial nerve tences that may be sound-alike words or words with similar yet incor- II and the efferent limb of the arc being cranial nerve III, which carries rect meanings. A global or mixed aphasia involves elements of fluent the pupilloconstrictors. A bright light directed into one eye should cause and nonfluent aphasias and is the most common type encountered in a brisk constriction of equal magnitude in both pupils. In the swinging clinical practice. flashlight test, observe the pupils as the light is slowly moved from one Nondominant hemisphere problems may show problems of auditory pupil to the other. A seemingly paradoxical dilation of one pupil as the inattention, visual inattention, or sensory inattention. light is moved onto that pupil may indicate optic nerve dysfunction of that eye; this is referred to as an afferent pupillary defect (see Chapter 241,  ADVANCED “Eye Emergencies”). Cranial nerves III, IV, and VI are concerned with extraocular eye Testing of mental status and cognitive function requires an appreciation movements (see Chapter 241). Tracing an object through a full-H pat- of cultural context and language barriers. Further assessment of com- tern allows assessment of the different cranial nerves. Cranial nerve VI prehension may involve showing the patient a picture and asking for innervates the lateral rectus muscle, which abducts the globe, moving it the patient’s interpretation of the picture while noting if the content is laterally away from the midline; this lateral movement will be impaired correctly described and if the sentence structure and word selection of or lost in the case of cranial nerve VI palsy. In fact, the unopposed the descriptions are correct. adduction movement of medial rectus muscle innervated by cranial nerve Assessing the ability of the patient to repeat a phrase may be a key III may result in the globe being medially deviated. Cranial nerve III point in delineating some types of fluent aphasias. Typically, the ability innervates the extraocular muscles that adduct each eye and those that to repeat short words is more impaired than the ability to repeat longer elevate and depress the globe. Impairment of cranial nerve III will reveal words. A classic test involves asking the patient to repeat the phrase, several abnormalities of extraocular movement, reflecting weakness in “No ifs, ands, or buts.” In one type of fluent aphasia, Wernicke’s aphasia, the innervated muscles. A complete paresis of cranial nerve III will show comprehension is impaired, as is repetition. a dilated pupil in a globe deviated downward and outward. An isolated Paraphasic errors may be further characterized in patients with flu- cranial nerve IV weakness may be hard to detect; cranial nerve IV sup- ent aphasia. Literal paraphasic errors are ones in which parts of words plies the superior oblique muscle that elevates and intorts the globe. are replaced by incorrect sounds. The use of spool when spoon is meant Cranial nerve III also carries the parasympathetic pupilloconstrictors is an example of a literal paraphasic error. At times, the errors may to the eye; a lesion of cranial nerve III may impair those fibers, resulting reach the point where the substitutions are not understandable, and in unopposed dilatation and a pupil larger than in the unaffected eye. neologisms (meaningless collections of syllables that take the place of a Ptosis from levator muscle paralysis may be another finding of cranial words in conversation) are produced. Verbal paraphasic errors involve nerve III paresis. substitutions of correct words for others; for example, a patient may Cranial nerve V has motor and sensory functions. It supplies the wish to use spoon in a sentence and substitute fork or even bike; the muscles of mastication and is assessed by appreciating the masseter Tintinalli_Sec14_p1101-1186.indd 1102 8/2/19 12:08 PM  CHAPTER 164: Neurologic Examination    1103 bulk. The sensory component of cranial nerve V supplies the cornea; neuroanatomy, at times, dissociation of these modalities occurs and the corneal reflex is a reflex arc involving cranial nerves V and VII. allows localization of problems to anatomic areas within the CNS. Cranial nerve VII supplies the muscles for facial movement as well as Practically establishing that touch or pinprick is perceived in all facial proprioception. extremities is often the only sensory assessment needed in a screening Cranial nerve VIII has auditory and vestibular afferent components. examination. However, if touch or pinprick is not intact or if peripheral Cranial nerves IX and X are tested by observing pharyngeal musculature nerve or spinal cord injury is suspected, additional detailed examination and gag reflexes. Cranial nerve XI is assessed by a shoulder shrug. Cra- is usually necessary. nial nerve XII controls lingual movement and can be assessed by asking Position testing is best used for the detection of peripheral neuropathy the patient to stick out the tongue and observing for any asymmetry of or posterior column spinal cord disease. Position and vibration sensa- motion. tions are conveyed in the posterior columns of the spinal cord, so that there is no need to test both position and vibration—just test one.  ADVANCED  ADVANCED In approximately 20% of the population, some degree of physiologic anisocoria on the order of 1 to 2 mm may be present. Small differences Spinal cord dermatome levels are illustrated in Figure 164-1. If sensory in pupillary size in otherwise asymptomatic patients likely represent alteration conforms to a level or selectively involves specific derma- this normal variant. A peripheral lesion of cranial nerve VII will cause tomes, further localization to the peripheral nerve or nerve root may complete facial paralysis on the same side as the lesion (“peripheral be possible. VIIth pattern”). A cortical lesion (often stroke) results in weakness of the If primary sensory modalities are intact, then testing of higher sen- lower and midface on the opposite side of the injury with preservation sory functions may be pursued; these are covered in the section on of motor function in the upper face (“central VIIth pattern”). This is due higher cerebral functions. to the bilateral cortical upper motor neuron innervation of the forehead musculature present in most patients.  SPECIAL CIRCUMSTANCES A few patterns of sensory loss are worthy of special mention. In cervical  SPECIAL CIRCUMSTANCES spinal cord injury or compression, an area of apparent sensory demarca- tion often appears to be just above the nipples. This transverse sensory In the comatose patient, a unilaterally dilated pupil that is unreactive or level suggests a spinal cord lesion in the low cervical to high thoracic reacts sluggishly to light may represent third nerve dysfunction or pare- area. Most cervical dermatomes are represented in the upper extremity sis from impingement of the oculomotor (III) nerve at the tentorium; and not in the trunk (see Figure 164-1), and further testing is necessary this finding is consistent with the uncal herniation syndrome. to delineate the sensory level. Vertigo often is a symptom from a vestibular system dysfunction but With suspected spinal cord injury, test the area of the perineum for may result from a CNS disorder such as posterior circulation stroke. sensation. The sacral dermatomes are distributed in an onion skin pat- Observe the patient for nystagmus while looking ahead; if nystagmus is tern around the perineum and are represented only in that region. The present while simply looking ahead, especially if vertical or direction- demonstration of a preserved island of sensation around the perineum changing, a central cause of vertigo is likely. If vertical skew gaze is may be the only sign of an incomplete spinal cord injury, which has a present or is provoked by alternately covering each eye with the patient different prognosis than a complete spinal cord injury. looking directly ahead, a central cause may also be present. Some general comments may be made about patterns of sensory The horizontal head impulse test (HIT) is a bedside maneuver to alterations. In general, a half-body sensory loss or alteration suggests detect peripheral vestibular disease.3 Assess the HIT by rapidly rotating cortical or subcortical lesions. A localized problem in one limb suggests the head to one side then the other while asking the patient to continue a peripheral nerve or nerve root problem, although there are other pos- to look at a target; normally the vestibular-ocular reflex involuntarily sible locations of abnormalities in the CNS.8 moves the eyes while maintaining visual fixation on the target. With peripheral vestibular problems, the inability to maintain visual fixation during head rotation results in a rapid corrective jerking (saccade) back MOTOR SYSTEM to the target; this is an abnormal HIT. In patients with acute persistent vertigo from stroke (central cause of vertigo), a normal finding with the There is more to evaluation of the motor system than simple assessment HIT (visual fixation maintained, no rapid saccadic movement observed) of strength. Muscle bulk and muscle tone are basic areas of assessment. reliably identified patients with a central cause of acute persistent ver-  BASIC tigo. However, an abnormal test (positive saccadic movement observed) occurred in patients with both peripheral and central causes of vertigo.4 Two additional maneuvers were advocated to be used in conjunction Muscle tone may be characterized as normal, decreased, or increased. with the HIT to reliably exclude central causes of vertigo. Examination Assess tone by movement of muscle groups and appreciating any resis- for nystagmus and assessment for skew gaze were added to HIT; this was tance to movement. Ask the patient to relax and not resist. Increased termed HINTS testing (head impulse, nystagmus type, test of skew).4,5 tone is greater than normal resistance to passive motion. Cogwheeling Nystagmus that changes direction with gaze to either side is predictive of is transient increase or catching in resistance followed by release to the a central lesion, as is spontaneous vertical or multidirectional nystagmus.6 movement. Assess axial or truncal tone by standing behind the patient, Skew deviation refers to misalignment of the eyes. Although subtle at grasping the shoulders, and gently moving the shoulders back and forth times, it may be unmasked by alternately covering each eye while the in a gentle rotation. A patient with normal tone will offer little resistance patient fixes gaze on the examiner.7 The HIT and HINTS exams have to repeated motions, and some spontaneous swing of the arms will be not been extensively analyzed in the ED setting. noted. A patient with increased axial tone (e.g., Parkinson’s disease) may turn without the arm swing. Simply having the patient hold the arms outstretched with palms upward and observing for any inward rotation or downward drift is SENSORY EXAMINATION a very sensitive sign for upper extremity weakness (pronator drift);  BASIC this also may be assessed in unresponsive patients (Figure 164-2). If both arms are held outright at the same time, comparison is easy, with The sensory evaluation can be key in some patients with sensory observation of the upper extremity of one side as opposed to the other. complaints. The primary sensory modalities are light touch, pinprick, A similar maneuver may be performed in the lower extremities. Another position, vibration, and temperature sense. Because of variability in sensitive test for a subtle hemiparesis is the forearm-rolling technique. Tintinalli_Sec14_p1101-1186.indd 1103 8/2/19 12:08 PM  1104   SECTION 14: Neurology FIGURE 164-1. Sensory dermatomes. With the forearms outstretched, ask the patient to make tight circles Tremor can be difficult to characterize, and there are many types of with each arm. The movements should be small and rapid. Asymmetry tremor. Action tremors, those that are absent at rest but evident with or slowness with one arm suggests a weak limb.9 Decreased speed of action or sustained limb position, include those from caffeine, hyperthy- foot tapping also may suggest weakness and an upper motor neuron roidism, and alcohol or sedative withdrawal. Essential familiar tremor problem.10 is also an action tremor. Rest tremors characterize Parkinson’s disease, with tremor present during rest, diminishing with willed movement, and then resuming with the new position. Assessment and recording of other motor strength are best done by description of the stimulus and response. For example, the fact that the patient is able to strongly resist elbow extension or elbow flexion against the examiner is an appropriate notation.  ADVANCED Compare muscle mass or bulk of the affected area with muscle groups of the unaffected areas. If weakness or paralysis has been present for some time, muscle wasting or atrophy may be present. Brief, rapid twitches of small parts of a muscle may represent fasciculations, which may indicate a process involving the lower motor neurons. A formal rating scale for muscle strength exists but is not straightfor- ward to apply. A rating of 5 is assigned for normal strength, and a rating of 4 indicates weakness and the ability to contract the muscle against some resistance. Thus, a tremendous range of strength is covered within the range of the 4 rating. A rating of 0 represents complete paresis, and a rating of 1 indicates a minimal flicker of contraction. A rating of 2 is assigned for active movement of a muscle with gravity eliminated by limb repositioning (e.g., so that elbow flexion and contraction are dem- onstrated by a horizontal rather than by a vertical movement). A value of 3 is assigned to a muscle able to voluntarily demonstrate full motion against gravity only. It is better for the examiner to describe the strength of a muscle by noting the amount of resistance than by invoking what FIGURE 164-2. Testing for weakness in the comatose patient; diagram illustrates may be a little-used scale and erroneously applying a rating. assessment of muscular tone in a patient with a right hemiplegia. A similar maneuver may be Listings of some muscle innervations, actions to test, and dermatomal used in the conscious patient. representations are found in Tables 164-1 and 164-2. Tintinalli_Sec14_p1101-1186.indd 1104 8/2/19 12:08 PM  CHAPTER 164: Neurologic Examination    1105 TABLE 164-1 Muscle Innervation: Shoulder and Upper Extremity TABLE 164-2 Muscle Innervation: Hip and Lower Extremity Nerve Action to Test Muscle* Nerve Action to Test Muscle* Long thoracic Forward shoulder thrust Serratus anterior Femoral Hip flexion Iliopsoas; T12, L1,† L2, L3 Dorsal scapular Elevate scapula Levator scapulae Leg extension Quadriceps femoris; L2, L3,† L4 Suprascapular Arm external rotation Infraspinatus; C5, C6 Obturator Thigh adduction Pectineus Axillary Abduct arm (>90 degrees) Deltoid; C5 Adductor longus, brevis, Musculocutaneous Flex and supinate arm Biceps brachii magnus; L2, L3, L4 Ulnar Ulnar flexion of hand Flexor carpi ulnaris; C7, C8,† T1 Gracilis Flex DIP of fingers 4 and 5 Flexor digitorum profundus Superior gluteal Thigh abduction Gluteus medius and minimus Thumb adduction Adductor pollicis; C7, C8† Thigh flexion Tensor fascia lata Abduction of finger 5 Abductor digitorum minimi Lateral thigh rotation Piriformis Opposition of finger 5 Opponens digitorum minimi Inferior gluteal Thigh abduction Gluteus maximus Flexion of finger 5 Flexor digitorum minimi brevis Sciatic (trunk) Leg flexion Biceps femoris; L5,† S1, S2 Finger abduction and adduction Interossei; C8, T1† Semitendinosus Flex PIP and extend DIP of Lumbricals 3 and 4 Semimembranosus fingers 4 and 5 Deep peroneal Foot dorsiflexion and Tibialis anterior; L4, L5 Median Forearm pronation Pronator teres supination Radial hand flexion Flexor carpi radialis; C7, C8, T1 Toes 2–5 and foot extension Extensor digitorum longus/brevis Hand flexion Palmaris longus Great toe and foot dorsiflexion Extensor hallucis longus PIP flexion of fingers 2–5 Flexor digitorum superficialis Superficial peroneal Plantar flexion foot and Peroneus longus/brevis; L5, S1 Abduct thumb at the Abductor pollicis brevis eversion metacarpophalangeal Tibial Plantar flexion and inversion Posterior tibialis Flex proximal phalanx thumb Flexor pollicis brevis; C7, C8† Flex distal phalanx toes 2–5 Flexor digitorum longus Anterior Flex DIP fingers 2–5 Flexor digitorum profundus interosseous (radial) Flex distal phalanx great toe Flexor hallucis longus Flex thumb interphalangeal Flexor pollicis longus Flex middle phalanx toes 2–5 Flexor digitorum brevis Oppose thumb Opponens pollicis; C8, T1† Flex proximal phalanx great toe Gastrocnemius; L5, S1,† S2 Flex PIP and extend DIP of Lumbricals 1 and 2 Knee flexion and ankle Flexor hallucis brevis fingers 2 and 3 plantar flexion Posterior Extension of digits 2–5 Extensor digitorum Ankle plantar flexion Plantaris, soleus interosseous Ulnar hand extension Extensor carpi ulnaris Pudendal Voluntary pelvic floor Perineal and sphincters; S3, S4 contraction Thumb abduction Abductor pollicis longus Thumb extension Extensor pollicis longus and * Dermatomal representations are listed after some muscles. brevis Predominant dermatome. † Index finger extension Extensor indicis proprius Radial Forearm extension Triceps brachii; C6, C7,† C8 Forearm flexion Brachioradialis; C5, C6 follows the stretching of muscle spindle fibers by the strike of the reflex Radial hand extension Extensor carpi radialis hammer and the involuntary muscle contraction that follows. Muscle Forearm supination Supinator stretch reflexes serve mainly to confirm evidence collected in other parts of the history or physical examination. Abbreviations: DIP = distal interphalangeal joint; PIP = proximal interphalangeal joint. Depending on the force of the reflex hammer strike and local impact * Dermatomal representations are listed after some muscles. factors, an elicited reflex may seemingly change from moment to † Predominant dermatome. moment. Make sure the patient and the muscle tested are relaxed. Often several reflex strikes are performed. Record the best response.  SPECIAL CIRCUMSTANCES Although not classically described as part of the motor system examina-  BASIC tion, information regarding bladder tone and function is at times vital Muscle stretch reflexes are graded on a scale from 1 to 4 that is not to the examiner. In patients with complaints of incontinence and low rigorously defined, with 0 representing the absence of reflex, 2 or 3 back pain, for example, discovery of a probable neurogenic bladder by being normal, and 4 representing hyperactive reflexes. Patterns of reflex demonstrating large US-assessed or postcatheterization residual urine abnormalities (e.g., upper vs. lower extremity, left vs. right) may suggest volume might be a key to diagnosis of spinal cord compression. What a location of a problem within the CNS or peripheral nervous system. is an abnormal postvoid residual bladder volume is difficult to say with The Babinski response is observation of the great toe moving upward certainty, and the literature is not clear on this point, but in general, a in response to a mildly noxious stimulation applied to the lateral plantar volume of >100 mL, or certainly 200 mL, is cause for concern. or lateral aspect of the foot. The application of stimuli should not be hard or forceful. In adults, the normal response of the toe is to move REFLEXES downward to plantar stimulation. The presence of a Babinski’s sign— that is, the abnormal reflex with movement of the great toe upward and Muscle stretch reflexes are the least important part of the neurologic perhaps fanning of the other toes—is the classic indicator of an upper examination and offer little value when used in isolation. Correctly motor neuron lesion. The reliability and accuracy of a Babinski’s sign termed muscle stretch reflexes, the jerk or involuntary motor movement have been called into question.10 Tintinalli_Sec14_p1101-1186.indd 1105 8/2/19 12:08 PM  1106   SECTION 14: Neurology FIGURE 164-3. Method for eliciting ankle clonus. FIGURE 164-4. Pronation and supination test: cerebellar testing.  ADVANCED  ADVANCED Clonus is the rhythmic oscillation of a body part, typically the ankle, Although usually included in cranial nerve testing, eye movements are elicited by a brisk stretch (Figure 164-3). It is one sign of spastic- useful in assessing cerebellar function, and abnormalities in their move- ity, in addition to a Babinski response (or slowing of foot tapping), ments may suggest cerebellar dysfunction. Tracking an object slowly increased muscle tone, and hyperactive muscle stretch reflexes. It may should show smooth, slow eye movements; breakup of the smooth be seen in conditions of metabolic disturbance and primary neurologic movement may be evident and is analogous to the decompensation of dysfunction. movements that may occur in isolated cerebellar impairment. Similarly, if a patient is asked to look back and forth between two objects (finger- to-nose testing involves the patient looking back and forth quickly  SPECIAL CIRCUMSTANCES between the examiner’s outstretched finger and nose), the eyes should quickly and conjugately look at the target without overshoot. These Disease processes involving upper motor neurons or their processes faster movements are, at least in part, reflective of intact cerebellar func- (cortical or spinal cord injuries) result in hyperactive reflexes, a tion. Nystagmus is rapid involuntary movements of the eyes that may Babinski response, and clonus. Processes injuring lower motor neu- be present with primary (straight-ahead) gaze or provoked by looking rons, their axons, peripheral nerve roots, peripheral nerves, or the at extremes of gaze. Coarse nystagmus or other abnormalities of eye muscles themselves may result in hypoactive reflexes. However, in movements are at times present with cerebellar problems (see discus- spinal cord injury or stroke, reflexes may take several hours or even days sion above under cranial nerve testing, or see Chapter 170, “Vertigo,” for to become hyperactive, so the absence of these signs is not valuable in more discussion of nystagmus). excluding acute spinal cord injury. Spinal cord emergencies are high-risk clinical scenarios. Although the presence of a Babinski’s sign and hyperreflexia are cardinal signs of upper motor neuron syndrome, the absence of these signs does not GAIT AND STATION reliably exclude a diagnosis of spinal cord compression; pursue the It has been said that, if only one neurologic test could be performed, diagnosis if historical or other physical examination findings suggest the observation of the patient walking would be the most informative. The possibility of this critical diagnosis.11,12 posture that the patient assumes when stationary defines the station of the patient. A variety of abnormal gaits and postures are discussed further in Chapter 169, “Ataxia and Gait Disturbances,” as are different CEREBELLAR TESTING techniques of physical examination. One feature common in many patients with cerebellar hemorrhage The cerebellum is concerned with involuntary activities of the CNS and is the sudden inability to walk. Keep the possibility of cerebellar injury is a structure that helps with smoothing muscle movements and aiding in mind when evaluating a patient with sudden onset of symptoms that with movement coordination. Very simply, the central cerebellar struc- include the inability to walk. Patients with cerebellar hemorrhage may tures may be thought of as controlling coordination of posture and trun- also have severe nausea and vomiting. Their clinical condition is such cal movements (axial coordination). The lateral cerebellar structures that fine neurologic examination is simply not possible. are more coordinated with movements of the extremities (appendicular coordination). Acknowledgments: The authors would like to acknowledge the work of Dr. Greg Henry and Dr. Hugh S. Mickel, authors of chapters on this topic in previous editions of the study guide. Their chapters served  BASIC as a check for completeness and provided some tabular information. J. Stephen Huff would like to acknowledge the influence of the late Rapidly alternating movements may be assessed by a variety of maneu- Dr. William DeMyer of Indiana University, whose instruction in the vers. Hand-slapping tests, asking the patient to rapidly pronate and then neurologic examination years ago stimulated an interest in this area. supinate the forearm, and slapping the thigh with each movement is a commonly used test. The movements are normally small, and the hand slapping should be symmetric. Rapid pronation and supination of the REFERENCES hands is another test for dystaxia and dysmetria; the movements should be equal with both hands (Figure 164-4). The complete reference list is available online at www.TintinalliEM.com. Tintinalli_Sec14_p1101-1186.indd 1106 8/2/19 12:08 PM  1107 CHAPTER 165: Headache    CHAPTER Headache TABLE 165-1 High-Risk Features for Headache: Clinical “Red Flags” Onset Sudden 165 Alex Koyfman Brit Long Trauma Exertion Symptoms Altered mental status Seizure INTRODUCTION AND EPIDEMIOLOGY Fever Neurologic symptoms Headache is the fourth most common symptom presenting to the ED in the United States, accounting for close to 3% of total ED visits.1 Overall, Visual changes headaches affect people across all ethnic, geographic, and economic Medications Anticoagulants/antiplatelets levels, with an estimated global prevalence of 47% in adults.2 Recent antibiotic use In the ED, the approach to headache focuses on identifying patients Immunosuppressants at risk for rapid deterioration, morbidity, and mortality; rapidly identify- ing high-risk headache syndromes; and providing appropriate headache Past history No prior headache therapy. Change in headache quality, or progressive headache worsening over weeks/months Associated conditions Pregnancy or postpregnancy status PATHOPHYSIOLOGY Systemic lupus erythematosus The brain parenchyma has no pain sensors.3 Early theories postulating Behçet’s disease vasoconstriction and rebound vasodilatation as the cause of migraine Vasculitis have been refuted.4 Numerous physiologic mechanisms play a role in the Sarcoidosis development of the various clinical headache syndromes. For example, occipital nerve irritation may lead to the development of occipital neu- Cancer ralgia.5 Similarly, headaches associated with disturbances in intracranial Physical examination Altered mental status pressure (high and low) are related to compression of, or traction on, Fever pressure-sensitive structures in the meninges.6 The pathophysiologic Neck stiffness mechanisms of other headache syndromes, such as migraine headaches, Papilledema cluster headaches, and toxic and metabolic headaches, are less clear. Discussion of these mechanisms is beyond the scope of this chapter. Focal neurologic signs CLINICAL FEATURES encephalopathy syndrome15 or reversible cerebral vasoconstriction syndrome.16 Headaches associated with the Valsalva maneuver may Although headaches are typically classified as primary headaches when herald an intracranial abnormality.17 Rarely, spontaneous intracranial there is no underlying cause (such as migraine, tension, or cluster head- hypotension and acute hydrocephalus associated with third ventricular aches) and secondary headaches if associated with an underlying cause colloid cyst may present with thunderclap headache.18 Other causes for (such as tumor, meningitis, or subarachnoid hemorrhage), this distinc- thunderclap headache are listed in Table 165-2. tion is not clinically useful in the ED setting. Rather, the emergency phy- sician should focus on evaluating for and ruling out secondary causes of Headache Quality A change in pattern, frequency, quality, or intensity headache. Most patients with headache have conditions that are painful of a preexisting headache syndrome needs the same evaluation as a new- but benign in etiology. Identifying those at high risk for a secondary onset headache syndrome. headache is the first step in management (Table 165-1). A high-risk Fever Fever raises concern for CNS infection, such as meningitis, cause for headache accounts for only 4% of all headaches but 10% to encephalitis, or brain abscess. However, the absence of fever does not 14% of acute-onset (“thunderclap”) headaches.7,8 Improvement of the exclude a CNS infection, especially in patients at the extremes of age and patient’s pain with treatment does not predict benign cause of headache. with immunocompromised states, such as human immunodeficiency virus. Headaches in patients with human immunodeficiency virus  HISTORY and CD4 count less than 200 cells/μL have a higher risk of intracranial pathology.19,20 Features associated with high-risk headaches are as follows: Patient Age Patients >50 years of age, with a new or worsening head- ache, represent a high-risk group.9 The incidence of migraine, cluster, TABLE 165-2 Causes of Thunderclap Headache and tension headaches decreases with age, raising the likelihood of omi- Hemorrhage Intracranial hemorrhage nous pathology for older patients.10 Close to 15% of patients over age 65 will have a dangerous secondary headache on neuroimaging,11 and those “Sentinel” aneurysmal hemorrhage over 50 have four times the rate of pathology.7 Spontaneous intracerebral hemorrhage Onset of Symptoms The abrupt onset of severe headache, or “thun- Vascular Carotid or vertebrobasilar dissection derclap” headache, requires immediate and thorough evaluation.12 A Reversible cerebral vasoconstriction syndrome (RCVS) thunderclap headache is defined by pain that reaches 7 out of 10 in less Cerebral venous thrombosis than 1 minute.13 Thunderclap headache associated with intracerebral Posterior reversible encephalopathy syndrome (PRES) aneurysmal leak (“sentinel hemorrhage” or “herald bleed”) may precede catastrophic aneurysmal rupture by days to weeks. Associated symp- Other causes Coital headache toms may include neck stiffness, nausea, vomiting, loss of conscious- Valsalva-associated headache ness, neurologic deficit, or altered mentation.14 Onset of thunderclap Spontaneous intracranial hypotension headache during periods of exertion raises suspicion for subarachnoid Acute hydrocephalus (e.g., colloid cyst obstructing third ventricle)18 hemorrhage or arterial dissection of the carotid or vertebrobasilar Pituitary apoplexy circulation. A headache with seizure, altered mental status, visual dis- turbance, or focal neurologic deficit may be due to posterior reversible Acute angle-closure glaucoma Tintinalli_Sec14_p1101-1186.indd 1107 8/2/19 12:08 PM  1108   SECTION 14: Neurology TABLE 165-3 Clinical Features Suggestive of Migraine normalized temperature suggests consideration for further evaluation of a possible CNS infection. The presence of fever in association with neck Prior history of migraine Moderate/severe intensity stiffness and altered mental status represents the classic triad of menin- Younger age Unilateral gitis. Close to 95% of patients with bacterial meningitis present with at Multiple prior episodes Throbbing least two of the four findings (classic triad plus headache).26 Aura and prodrome Nausea/vomiting Severe hypertension can be associated with headache and the devel- Familiar triggers Photophobia/phonophobia opment of acute changes in mental status and neurologic function. Con- sider posterior reversible encephalopathy syndrome27 and hypertensive Family history Lasts hours emergency in such patients (see “Posterior Reversible Encephalopathy History of motion sickness Syndrome” section). Examination of the Head and Neck Meningismus is an important clinical clue to the presence of infection or hemorrhage.26 Examine the Past Medical History The past medical history is essential in deter- ears, nose, and throat to identify otitis media and sinusitis, both of which mining risk of secondary etiology for headache. A history of immu- may cause headache and contribute to the extension of infection to the nocompromised state (including human immunodeficiency virus, CNS. Palpate for scalp tenderness and tenderness over the temporal vasculitis, diabetes, among others) may prompt need for further evalu- arteries to assess for possible temporal arteritis. ation. History of malignancy, trauma, current pregnancy, and recent Examination of the Eye Headache can occur with acute angle-closure pregnancy are suggestive of a secondary cause of headache. glaucoma, scleritis, and endophthalmitis. Visual complaints require Medication History Inquire about over-the-counter medications, consideration of secondary etiology. Consider acute angle-closure anticoagulants, antiplatelet agents, chronic steroids, immunomodula- glaucoma even when there is no focal ocular complaint, as the pain tory agents, or antibiotics (prescribed or not) to identify patients at high can be so severe the patient may fail to localize pain to the eye. Measure risk for infection (e.g., eculizumab and its elevated risk for meningococ- intraocular pressure to exclude glaucoma. Check visual acuity and visual cal infection). Chronic use of analgesic and anti-inflammatory agents fields and examine the pupils and eyelids, checking for signs of Horner’s may result in rebound or withdrawal headaches. Medication overuse syndrome. is defined as use >10 times a month and is notable for ergots, triptans, Funduscopic Examination Papilledema can be seen in the presence and opioids.17 Anticoagulants and antiplatelet agents increase the risk of raised intracranial pressure. However, there is typically a delay in the for hemorrhage, both spontaneous and traumatic.21 The recent use of onset of papilledema once intracranial pressure begins to elevate, and antibiotics may present with a falsely reassuring clinical appearance due papilledema can persist once intracranial pressure returns to normal.28 to partial treatment of a potentially dangerous CNS infection. The ability to recognize papilledema by routine direct ophthalmoscopy Prior Headache History A prior history suggestive of migraine, ten- alone (particularly with nondilated pupils) is limited, but a panoptic sion, or cluster-type headaches and response to specific therapy may ophthalmoscope provides a more reliable view of the retina.29 Bedside obviate the need for extensive ED evaluation (Tables 165-3 and 165-4). US of the optic nerve sheath can also assess for papilledema.30,31 The presence of papilledema requires CT imaging before lumbar puncture.32 Substance Use History Use of adrenergic agents such as cocaine, amphetamine, or derivative compounds such as methamphetamine Neurologic Examination A baseline neurologic assessment includes increases risk of intracranial hemorrhage or the less common entity of the following: mental status assessment; cranial nerve examination, reversible cerebral vasoconstriction syndrome.22 Patients with a history including pupillary examination (for asymmetry or ptosis, which may of alcohol abuse are at increased risk of intracranial bleeding due to falls, suggest third nerve compression by posterior communicating artery interpersonal violence, and the potential for liver dysfunction associated aneurysms); assessment for other cranial neuropathies (which may raise with prolonged coagulation times and thrombocytopenia. suspicion for carcinomatous meningitis); motor examination to detect extremity weakness (particularly subtle weakness with pronator drift); Family History Known aneurysm or sudden death in first-degree reflex examination for subtle asymmetry or a Babinski reflex; and gait relatives raises the suspicion for intracranial aneurysm.23 The inci- and coordination testing (which may be impaired in cerebellar lesions). dence of aneurysm in patients with a family history is three to five Any neurologic deficit, including altered mental status, possesses the times higher than in those without a family history. A personal or highest predictive value for CNS pathology.33 family history of autosomal dominant polycystic kidney disease also increases the risk for intracranial aneurysm. In patients with autoso- mal dominant polycystic kidney disease, aneurysmal rupture is more DIAGNOSIS likely to occur at a younger age. The presence of migraine in a first- degree relative is associated with a two- to fourfold increased risk of There are many causes of headache, each of which is diagnosed and developing migraine.24 managed differently.  PHYSICAL EXAMINATION  LABORATORY TESTING Vital Signs Headache is a common symptom associated with fever, as Routine blood testing is of limited utility in the diagnosis of acute head- headache is seen in up to 60% of patients with upper respiratory tract ache and should be guided by the patient’s age, history, relevant comor- infection symptoms.7,25 The persistence of headache in the presence of a bidities, and medication history. The laboratory evaluation of patients with high-risk headaches may include basic metabolic profile, CBC, coagulation panel, erythrocyte TABLE 165-4 Clinical Features Suggestive of Cluster Headache sedimentation rate, C-reactive protein, and blood cultures for possible infection. At least 5 attacks that meet the following Associated ipsilateral symptoms criteria: (at least one): Severe Lacrimation  IMAGING Unilateral Conjunctival injection Selecting an appropriate imaging study depends on the history, physi- Lasts 15–180 min (untreated) Nasal congestion or rhinorrhea cal examination findings, and differential diagnosis of headache,34-36 as Circadian/circannual pattern Ptosis and/or miosis well as the resources available to the emergency provider. Table 165-5 Edema of the eyelid and/or face summarizes some of the American College of Radiology and American College of Emergency Physicians recommendations for appropri- Sweating of the forehead and/or face ate imaging. When MRI is immediately unavailable and diagnostic Tintinalli_Sec14_p1101-1186.indd 1108 8/2/19 12:08 PM  1109 CHAPTER 165: Headache    TABLE 165-5 Choice of Imaging Modality  LUMBAR PUNCTURE American College of Radiology After the clinical assessment, blood work, and imaging, the next step Noncontrast Head CT MRI of Brain With and Without Contrast is to determine whether to perform a lumbar puncture (LP) and, if so, the timing of LP. LP can serve as both a diagnostic tool (as in men- Trauma N ew-onset headache plus focal neuro- ingitis, subarachnoid hemorrhage, intracranial hypotension, carcino- Thunderclap headache logic deficit/papilledema matous meningitis) and therapeutic tool (as in idiopathic intracranial New headache plus focal neurologic Possible encephalitis hypertension). deficit or papilledema Possible vertebral/carotid dissection Ideally, perform the LP with the patient in the lateral decubitus posi- Chronic headache plus change in clinical Horner’s syndrome tion to allow for the accurate measurement of opening pressure. Seated features LP does not allow for accurate assessment of opening pressure. Opening Valsalva or coital headache pressure provides critical information about the patient’s intracranial Immunocompromised individual pressure and should be considered a routine procedure when perform- Patient with cancer history/current ing LP. cancer The possibility of herniation in association with LP is a frequent con- Suspected temporal arteritis cern of emergency providers. There is no randomized controlled trial Intracranial hypotension (low-pressure assessing the question of when it is safe to perform an LP. The cumu- headache) lative evidence suggests that in patients with normal sensorium, no focal neurologic deficit, and without a history of immunosup- Headache with suspected intracranial pression, it is safe to proceed with LP without imaging prior to the complication of sinusitis/mastoiditis/ procedure.40,41 oromaxillofacial origin In the evaluation of patients with suspected acute bacterial menin- New-onset headache in pregnant gitis, clinical signs of “impending” herniation are the best predictors of woman (without contrast) when to delay an LP because of the risk of precipitating herniation. Risk Headache of trigeminal autonomic of an abnormal CT scan is elevated in patients with any of the following origin clinical features: a deteriorating or altered level of consciousness (partic- Chronic headache with new feature or ularly a Glasgow Coma Scale score of ≤11), brainstem signs (including focal deficit (CT can be first step) pupillary changes, posturing, or irregular respirations), focal neurologic American College of Emergency Physicians 2008 Clinical Policy: Which patients with deficit, history of recent seizure, history of a preexisting neurologic dis- headache require neuroimaging in the ED? order, or history of immunocompromised state. In patients with these clinical features, imaging prior to LP is appropriate, but never delay Patient Presentation Recommendation antibiotic administration while imaging is obtained. In patients without Headache and new abnormal findings Level B (emergent noncontrast head CT) such findings, it is usually safe to perform LP without obtaining a CT in neurologic examination (focal deficit, scan in cases of suspected bacterial meningitis.42 altered mental status, altered cognitive function) DISPOSITION AND FOLLOW-UP New sudden-onset severe headache Level B (emergent noncontrast head CT) HIV-positive patients with a new type of Level B (emergent noncontrast head CT) Most patients with headache can be treated and released from the ED headache with an appropriate follow-up plan. Identification of potential barriers to follow-up is an important step in ensuring that proper follow-up Age >50 with new headache but with Level C (urgent noncontrast head CT) will be available to all patients, particularly for patients with limited normal neurologic examination resources or other barriers to accessing medical care. For some patients, inpatient care or observation may be warranted until symptoms improve or until testing is completed. A follow-up plan is important for patients with high-risk conditions, such as temporal arteritis or uncertainty regarding the possibility of an underlying lesion prevails, idiopathic intracranial hypertension. Follow-up is similarly important further imaging may be necessary, the timing of which will depend on for patients with chronic headaches, given the potential for substance the clinical circumstances and likelihood of the patient being able to abuse, overutilization of resources, and repeated unnecessary imaging follow up in a reliable fashion.34 with potentially harmful radiation.35 If the patient presents with a typical history of headache that responds to typical measures and a normal neurologic examination, avoid neuro- SPECIFIC CAUSES OF HEADACHE imaging to reduce radiation exposure. When appropriate, a noncontrast  MENINGITIS/ENCEPHALITIS head CT is the fastest and most appropriate initial imaging study, as well as the most sensitive for detecting acute intracranial hemorrhage.36,37 Gadolinium-based magnetic resonance contrast agents are contrain- Consider meningitis and encephalitis in patients with headache and the dicated for patients with renal insufficiency due to risk of nephrogenic classic triad of fever, altered mentation, and neck stiffness.26 Meningitis systemic fibrosis, and intravenous contrast for CT should be carefully is due to the meningeal infection and inflammation, while encephalitis considered in patients with renal insufficiency, although literature sug- results from infection and inflammation of the underlying neural tissue. gests no association of contrast with renal injury.38,39 Gadolinium is The combination of headache, fever, and neck stiffness is present in 44% relatively contraindicated in pregnancy and breastfeeding women. MRI of cases of meningitis, although 99% of patients will have at least one can be limited by claustrophobia. A discussion with the radiologist and/ of these symptoms.26 The source of infection in meningitis can be viral, or radiology technical staff can clarify the safety of MRI in patients with bacterial, and less commonly, fungal or parasitic, with similar etiologies devices or foreign bodies. in encephalitis, although viral causes are most common. Have a high Magnetic resonance angiography is useful in detecting arterial index of suspicion for meningitis in those with immunosuppression disease (stenosis, congenital anomalies, dissection, CNS vasculitis) and (particularly acquired immunodeficiency syndrome, human immu- should be considered in any case where there may be arterial pathology nodeficiency virus, cancer history, chemotherapy, chronic steroids), underlying the patient’s symptoms. Discuss concerns for dissection with which may be associated with more insidious types of meningitis such the radiologist to determine the most appropriate MRI method. as Cryptococcus. An LP is indicated for suspected meningitis. If the If MRI is unavailable or not clinically feasible, consult radiology LP is delayed (e.g., CT, coagulopathy, thrombocytopenia, agitation) regarding other appropriate imaging modalities. and meningitis is strongly suspected, administer antibiotics without Tintinalli_Sec14_p1101-1186.indd 1109 8/2/19 12:08 PM  1110   SECTION 14: Neurology delay.32,43 For many patients who are awake and alert without evidence barriers to access of medical care in clinical decision making, because of papilledema or focal neurologic deficit and who have no history to additional imaging may be needed at follow-up. suggest immunocompromised state or new-onset seizure, the head CT  CEREBRAL VENOUS THROMBOSIS can be delayed until after the LP.32  SUBARACHNOID HEMORRHAGE Cerebral venous thrombosis is a rare, but dangerous, cause of headache, with mean age of 39 years. Consider the diagnosis in patients present- Subarachnoid hemorrhage resulting from rupture of an intracranial ing with new headache symptoms, especially in the presence of certain aneurysm carries only a 50% 30-day survival rate.44,45 Approximately half risk factors. Cerebral venous thrombosis is more common in women, of survivors have some degree of neurologic impairment. Early detection especially in the peripartum period, and in patients with a recent surgi- and appropriate management lead to improved clinical outcome. Only 1% cal history. It is associated with hypercoagulable states such as use of of patients presenting to the ED with headache have subarachnoid hemor- oral contraceptives, hematologic disorders, factor V Leiden homozygous rhage. However, 10% to 14% of those complaining of the “worst headache mutation, protein S or protein C deficiency, and anti–thrombin III defi- of their life” have subarachnoid hemorrhage.7,8 Acute onset of a severe ciency.61 The presentation can vary widely, from a progressive headache headache is subarachnoid hemorrhage until proven otherwise.12,14 Neck developing over days to weeks to, in some instances, a “thunderclap” pain on history and stiffness on exam are suggestive.46 Inquire about a headache. Similarly, the patient’s clinical appearance can be quite family history as outlined above.23 Obtain a noncontrast head CT as the benign, especially early in the course of the illness, or in more severe first step in evaluation.47 With third-generation CT equipment, CT scan cases, patients may present with signs of elevated intracranial pressure, done within 6 hours of headache onset is reported to have a sensitivity seizures (40%), stroke symptoms, and even coma (14%).62,63 Approxi- approaching over 99% and specificity over 99%, with a negative predic- mately one third will develop intracerebral hemorrhage.64 tive value of 99.4% and positive predictive value of 100%.46,48 If head In the presence of abnormal imaging (CT, MRI), focal neurologic CT is negative for blood but suspicion for subarachnoid hemorrhage is deficit, or altered mental status, the diagnosis is made definitively with strong, or if the patient presents beyond 6 hours of headache onset, the magnetic resonance venography. Given the rare nature of this diagnosis, next step is LP to detect blood or xanthochromia in the cerebrospinal patients suffering from cerebral venous thrombosis may be undergoing fluid.49 For further discussion, see Chapter 166, “Spontaneous Subarach- evaluation for other causes of severe headache. An elevated LP opening noid and Intracerebral Hemorrhage.” Consultation with a neurologist pressure should raise suspicion of cerebral venous thrombosis in the or neurosurgeon may be appropriate if the history is highly sugges- appropriate clinical setting and prompt further imaging with magnetic tive of subarachnoid hemorrhage, because both the CT and LP can be resonance venography or consultation with a neurologist.65,66 LP can normal.50-52 CT angiogram, magnetic resonance angiogram, MRI with safely be performed in patients with cerebral venous thrombosis. fluid-attenuated inversion recovery/susceptibility-weighted images,53,54  POSTERIOR REVERSIBLE ENCEPHALOPATHY SYNDROME or four-vessel cerebral angiogram may be reasonable.34  SUBDURAL HEMATOMA AND INTRACEREBRAL HEMORRHAGE Patients with posterior reversible encephalopathy syndrome can present with severe headache, visual changes, seizures, and encephalopathy in the Intracranial hemorrhage may occur with or without a history of trauma, setting of marked blood pressure elevation (usually rapidly developing). It in the context of new or progressive headache, and with or without asso- is most common in patients undergoing active treatment with immune- ciated neurologic deficit. This is particularly important in the elderly, suppressing or -modulating medications or chemotherapeutic agents, those with chronic alcohol and substance abuse, and patients using as well as in patients with end-stage renal disease. Imaging with MRI antiplatelet and anticoagulant agents. The antiplatelet agent clopido- typically shows evidence of symmetrical vasogenic edema in the occipital grel increases the risk of acute intracranial bleeding immediately after area of the brain, although other areas of the brain can be involved. Treat- trauma, so patients receiving antiplatelet agents and anticoagulants ment involves blood pressure control and supportive care.67 should be screened using head CT, regardless of symptoms. In a pro- spective trial of patients with blunt head trauma, 12% of those taking  REVERSIBLE CEREBRAL VASOCONSTRICTION SYNDROME clopidogrel and 5.1% of those taking warfarin had acute intracranial hemorrhage noted on their initial CT scan. The risk of delayed intra- This condition can mimic subarachnoid hemorrhage (see Table 165-2). cranial hemorrhage was small in both groups (0 of 296 patients taking Characterized by the occurrence of one or more “thunderclap” head- clopidogrel and 4 of 687 patients taking warfarin).21 aches, the diagnosis should be considered only when the evaluation Acute headache with associated vestibular symptoms (vertigo or for subarachnoid hemorrhage has proven negative. The underlying ataxia) should be considered a cerebellar hemorrhage until proven oth- pathophysiology of the syndrome is poorly understood, but it appears erwise. Cerebellar hemorrhages make up approximately 10% of all intra- to coexist with a number of other cerebral angiopathies (including cerebral hemorrhages and may require prompt surgical evacuation of the posterior reversible encephalopathy syndrome) that are characterized hematoma to prevent rapid progression to severe disability or death.55 by diffuse cerebral vasospasm. The incidence is greater in women, and the peak age of onset is in the early 40s. Most patients will have more  BRAIN TUMOR than one thunderclap headache over the course of a few weeks. Severe headache may be the only presenting feature, although some patients Headache in the setting of brain tumor is caused, at least in part, by can present with seizure or focal neurologic deficit. The key diagnostic cerebrospinal fluid flow obstruction and intracranial hypertension.56 feature (multiple areas of cerebral vasoconstriction on cerebral angiog- Headache alone is a rare presentation of brain tumor.57 Clinical signs raphy) is most commonly found on follow-up angiography between 2 and symptoms suggesting brain tumor include abnormal neurologic and 3 weeks after symptom onset.22 In three published series, the rate of examination, headache worsened by Valsalva maneuver, headache caus- permanent neurologic disability was between 6% and 20%. Reversible ing awakening from sleep, seizures, recent cancer diagnosis, or mental cerebral vasoconstriction syndrome, although not widely known among status change. The absence of these features does not exclude the pos- nonneurologists, does not appear to be that rare. One prospective case sibility of a brain tumor. In adults, nausea, vomiting, and neurologic series included 67 patients diagnosed at a single hospital over a 3-year deficit are more common than morning or nocturnal headache.58,59 MRI period of data collection.68 with and without gadolinium is the study of choice for detecting brain Initial neuroimaging in these patients may show evidence of nonaneu- tumors, but cost and limited access make it unfeasible in many settings. rysmal subarachnoid hemorrhage, ischemic stroke, or intracranial hem- A noncontrast CT will identify large masses and edema associated with orrhage. However, head CT is most commonly normal in these patients. large masses, but may fail to identify smaller masses. However, noncon- Ultimately, there will be magnetic resonance angiography evidence trast CT can diagnose hemorrhage secondary to malignancy, account- of cerebral vasoconstriction in all patients, but this may be delayed in ing for up to 11% of intracerebral hemorrhages.60 Evaluate for potential appearance. As such, the clinical presentation of thunderclap headache Tintinalli_Sec14_p1101-1186.indd 1110 8/2/19 12:08 PM